基于自组装和溶胶-凝胶法固定超氧化物歧化酶的直接电化学

Direct Electrochemistry of Superoxide Dismutase Immobilized by Self-assembly and Sol-gel Method

研究了在L-半胱胺酸存在下超氧化物歧化酶(SOD)固定于硅溶胶-凝胶中的电化学行为,实现了酶的直接电子传递,并且提高了其峰电流的响应,详细研究了影响酶电极制备的多种因素。制备的酶电极对超氧阴离子具有很快的安培响应,测定超氧阴离子的线性范围为0.1-0.8μmol/L,相对标准偏差为4.2%(n=8)。该方法综合了自组装和溶胶-凝胶技术的优点,电极制备简单,酶电极具有较高的灵敏度和良好的稳定性。

The direct electrochemistry of superoxide dismutase （SOD） immobilized in silica solgel film in the presence of cysteine on gold electrodes was investigated. The immobilized superoxide dismutase realized direct electron transfer between the enzyme and electrode surface, and the peak currents of SOD were markedly enhanced. The performance and factors influencing the performance of the resulting biosensor were studied in detail. The resuiting biosensor exhibited fast amperometric response to superoxide anion. The range of the determination for superoxide anion was 0.1 -0.8 μmol/L and the relative standard error was 4.2% （ n = 8 ）. The proposed method exhibited the benefits of the advantages of self - assembly and sol - gel techniques. The fabrication of the SOD - modified electrode was easy and simple. The biosensor exhibited high sensitivity and long- term stability.